We have established long-term epithelial cell cultures from the human fetal colon mucosa. The cell cultures exhibit characteristics of normal cells such as finite life span and a diploid modal of 46 chromosomes. The objective of this continuation grant application is to establish an in vitro transformation system using human normal colon epithelial cells as the specific target cells. Once such a system has been established and parameters of neoplastic transformation delineated, then the experimental system can be used to study in detail the cellular and molecular events associated with the transformation of normal human cells to neoplastic cells. Another important object is to identify differences in 3H-glucosamine labeled glucoprotein profiles between the normal and lines of transformed and tumorigenic cells. The differences in the glycoprotein profiles may serve as important markers for the degree of transformation of the colon epithelial cell cultures. The N-methyl-N'-nitro-N'-nitrosoguanidine is selected as a carcinogen because it is a complete carcinogen and the ability of the colon epithelial cells to metabolize incomplete carcinogens has not been studied. The transformation of cells will be quantitated by using parameters of morphological changes and anchorage independent growth. The tumorigenicity of the transformed cells will be examined by inoculation of transformed phenotypes into nude mice. The 3H-glucosamine labeled protein profiles will be studied by two-dimensional gel electrophoresis. The long-term objective is to compare phenotypic alterations of in vitro transformed colon epithelial cells and the subpopulations derived from tumors of the human colon.